As semiconductor manufacturers have sought to be able to fabricate devices having a higher degree of circuit integration to improve device performance, it has become necessary to use photolithographic techniques using shorter wavelengths in the mid and deep UV spectra to achieve fine features. In the process of making the desired very fine patterns many optical effects are experienced which lead to distortion or displacement of images in the photoresist that are directly responsible for wiring line width variations, opens and shorts, all of which can lead to deteriorated device performance. Many of these optical effects are attributable to substrate geometry and reflectivity influences that include halation and other reflected light scattering effects which may be due to uneven topography or the varying (wavelength dependent) reflectivity of the substrates and wires or layers being patterned thereon to define the desired features. Such effects are further exacerbated by both the non-uniformity of the photoresist film and film thickness. These effects are manifested in lithographic patterns uneven line width, often with "reflective notching", due to standing wave phenomena, non-vertical pattern sidewalls.
U.S. Pat. No. 4,910,122 to Arnold et al. is directed to processes for overcoming the reflectivity problems experienced in thin film lithography used in the fabrication of circuits of increasing density or integration. The process uses an antireflective film composition comprising a polymer having low surface energy (and which may incorporate a dye compound) as a layer interposed between the substrate and the imaging layer which reduces the dilatory reflective effects and which is removable by the photoresist developer.
It has been discovered that such processes are not compatible with chemically amplified resist compositions. Chemically amplified photoresist compositions are those in which the reaction continues through a mechanism that involves image formation of photoacid production and secondary acid production affects. An example of such composition is found in U.S. Pat. No. 4,491,628 to Ito et al. The codevelopable antireflective coatings adversely react with the components of the photoresist.